Waterproof connection for spark-plugs



A. SCHMIDT.

WATERPROOF CONNECTION FOR SPARK PLUGS.

APPLICATION FILED NOV. 30, 1911.

' Patented Aug. 24, 1920.

@Ali- Cltlgoznmws uNarED 'si-'raft151s 'PATENIOFFICL ALBERT SCHMIDT, orI'LINT, MICHIGAN, AssIGNoIt To CHAMPION I or FLINT, MICHIGAN, ACORPORATION or MICHIGAN.

WATERPROOF CONNECTION ron. slrAqaxFPImcfa.y

specification' of Letters Patent. Patented Aug. 24, 1920.

Application mea Noventa so, 1917. serial No. 204,550.

To all w hom 'it may concern:

Beit known that I, ALB'ERT SCHMIDT, av

citizenof the Republic of France, residing at Flint, in the county ofGenesee and State of Michigan, have invented certain new q and usefulImprovements in Waterproof Connecti n's for Spark-Plugs, of which thefollowing is a specification, referencebeing had therein to theaccompanying drawings. The invention relates to spark-plugs and has'forone object the protection of the insulator from accidental shocks whichmi ht cause a fracture or breaking thereof. nother-object is to providemeans coperating with the guard orvprotecting means for inclosing andweather-proofing the insulator and its electrical connection.

In the drawings: v

Figure l 's a longitudinal section through a sparkp1ug to which myimprovement is applied;

ig. 2 .is a perspective view thereof;

Fig. 3. is a view similar to Fig. 1 showi-ng a modified construction;and F Fig. 4 is a cross section ony lline 4 4 of i 1.

n the construction of spark-plugs it is usual to provide a'metalliccasing for ensuflicient distance to prevent l danger ofshort-circuiting. In attaching or detaching the spark-plug itfrequently' occurs that the wrench or other tool employed for thisoperation may strike against the insulator and as the latter is veryfragile it is easily fractured so as to destroy its -insulatingproperty. It is possible to guard the insulator either byextending thecasing so asA to Surround the same or by shortening the project, ingportion, but with either of these constructions the space between theinsulated terminal and the grounded vcasing would be diminished to anextent' that would danger short-circuiting.'

With my improved construction I pro;

vide a guard which will mechanicallyfprd. tect the insulator, togetherwith means for' preferably by engaging ai turned flange bracing the hoodand having breakage,

, centrically about thel projecting ortion o'f the insulator and forminga guar therefor. o avoid short-circuiting I provide a hood or cap memberF of insulating material, whlch has a sleeve portion Grv for fittinwlthm the tube D and ashoulder portion II for bearing against the outerend thereof. This hood has connected ed conductor I, able means,invention, with a contact member J for oooperating with the contact C. fThe hood F may be locked in position by 'an .suitable clamping means,such as the vmem r K eminwardly-exhooks L fon en aglng rojecting 'onthetube D. 'liIie lugs may be which lis connected by suittendin lugs cammed or wedge shaped, and thus byl slightly turmng the hood maybeengagedv with the hooks and at the same time will exert a drawingpressure'thereon'. N is a spring rcatch for engaging one of' the lugsand locking'the hood from rotative movement.- r

' With the vconstruction asdescribed, when the hood'isin position, itnot only incloses theinsulatorand electrical terminal thereon, but alsointerposes a'nf insulator guard between the terminal and the guardcasingD. Whenever it is desired to engage or remove the plu this may beaccomplished with perfect sa ety, as the tube D will guard the insulatorfrom-any contact-with the wrench or tool and will therefore avoid dangerof In thev construction shown in Fig. 3 in place of ahood-for inclosingthe terminal anA insulator is Lprovided .for insertion bevmountedthereon and extending inward-into electrical connection with the contactC. What I claim'as my invention' is:

and projecting-beyond the outerjend thereof, an electric terminal attheouter end of said insulator, and means at the outer end of. saidcasing for securing said insulator therein, of a metallic tube secured4to said casing and `projecting outward to surround said insu-- lator, adetachable hood for inclosing said insulator and terminal, having asleeve portion for fitting within said tube and sep- GNITION COMPANY,

thereto the insulat- '1. The covnibination with a sparkl plug.comprising ',acasing, anfinsulato'r therein C forming no part of thepresent;

arating the same from said terminal, and a cooperating electricalcontact for said terminal mounted on said hood.

2. The combination With a spark plug,

comprising a casing, a one-piece insulator therein and projectingoutward beyond the outer end thereof, an electric terminal at the outerlend of said insulator, and a turned flange at the outer end of saidcasing for securingsaid insulator therein, of a tube secured to saidcasing and projectingr outward to surround said insulator, a hood forin- .closing said insulator and terminal having a sleeve portion fittingWithin said tube and separating the same from said terminal, .acoperating electrical contact for said terminal mounted on said hood,and clamping means for securing said hood engaging said tube.

3. In a spark plug, the combination with a casing, an insulator thereinand projecting therefrom and an electrical terminal at the outer end ofsaid insulator, of a tube upon said casing and projecting therefrom tosurround said insulator, a detachable hood for inclosing said insulator,a member embracing said hood and cooperating cammed clamping membersupon said member and tube for securing said hood to said tube.

4. In a spark plug, the combination With a casing, an insulator thereinand projecting therefrom and an electrlcal terminal at the outer end ofsaid insulator, of a tubeupon said casing and projecting therefrom tosurround said insulator, a detachable hood for inclosing said insulator,a member embracing said hood, relatively rotatable cooperating clampingmembers upon said member and tube for securing said hood to said tube,and means for locking said members from relative rotative movement.

5. In a spark plug, the combination with a casing, an insulator thereinprojecting therefrom and an electrical terminal at the outer end of saidinsulator, of a metallic tube secured to said casing and projectingAout- Ward to surround said insulator, spaced lugs upon said tube, adetachable hood for in closing said insulator and terminal, having asleeve portion for fitting Within said tube and separating the same fromsaid terminal, and a member embracing said hood and havinginwardly-extending hooks rotatably engageable with said lugs forclamping said hood to said tube, said member embracing the hood beingrotatable about the axis of said insulator to permit of engagement ofsaid hooks With said lugs.

In testimony whereof I affix my signature.

ALBERT SCHMIDT.

